So, far, we have already learnt the shortcuts, how to multiply of any 2-digit and 3-digit number using criss-cross multiplication technique. In this tutorial, we will see how to multiply any 4 digit numbers.
Now Let’s try to understand the criss-cross multiplication technique to multiply any 4 digit numbers. As you know, the number of steps when multiplying any 4-digit numbers is 7.
Let us consider a simple example 3215 x 4231.
The step-by-step procedure can be explained with the following figure:
Notice the carry-forward in each stage of the multiplication. I hope, The steps are self – explanatory. Notice the additional steps compared to 2 x 2 and 3 x 3 multiplication.
Exercise : On the similar lines, can you multiply?
Multiplication when the number of digits are unequal
If the number of digits in multiplicand and multiplicand is unequal, you add zeros so that the digits have the same number of digits.
Let us consider an example. Suppose you have to multiply 4125 x 511. So, the number of digits are 4 and 3 respectively.
So, we convert 511 to 05111 and use this technique.
The multiplication steps are illustrated in the following figure :
Exercise : Can you multiply?
- 12 x 145
- 222 x 4223
- 92 x 9
- 52 x 125
If you have any doubts using this shortcut, please leave a comment or contact me. I would be glad to help.